Dynamically distributed file system

• US 20020138559A1
• Filed: 01/29/2002
• Published: 09/26/2002
• Est. Priority Date: 01/29/2001
• Status: Abandoned Application

• Current Assignee: Braodband Storage LLC, Snap Appliance, Inc. (Silicon Valley Technology Partners LLC)
• Original Assignee: Adaptec Incorporated (Steel Partners Holdings LP)
• Inventors: Schweitzer, James R., Bolstad, Gregory D., Staub, John R., Randall, Jay G., Priester, Wilbur George, Ulrich, Thomas R.
• Application Number:
  US10/060,930
• Publication Number:
  US 20020138559A1
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: G06F 16/10 File systems; File servers

Abstract

A dynamically distributed file system is described. The dynamically distributed file system operates on a computer network and includes a first file server that is operably connected to a network fabric and a second file server that is operably connected to the network fabric. The dynamically distributed file system further includes first file system information loaded on the first file server and second file system information loaded on the second file server. The first file system information and the second file system information are configured to allow a client computer that is operably connected to the network fabric to locate files stored by the first file server and files stored by the second file server without prior knowledge as to which file server stores the files.

Claims

1. A computer network file system, comprising:

a first file server operably connected to a network fabric;

a second file server operably connected to the network fabric;

first file system information loaded on said first file server; and

second file system information loaded on said second file server, said first file system information and said second file system information configured to allow a client computer operably connected to said network fabric to locate files stored by said first file server and files stored by said second file server without prior knowledge as to which file server stores said files.

2. The computer network file system of claim 1, wherein said first file system information comprises first directory information that describes a directory structure of a portion of the network file system whose directories are stored on said first file server and second directory information that describes a directory structure of a portion of the network file system whose directories are stored on said second file server, said first directory information comprising location information for said second directory information, said location information comprising a server id that identifies said second file server.

3. The computer network file system of claim 2, wherein said first directory information comprises a root directory.

4. The computer network file system of claim 1, wherein said first file system information comprises directory information that describes a directory structure of a portion of the network file system whose directories are stored on said first file server, said directory information comprising location information for a first file, said location information comprising a server id that identifies at least said first file server or said second file server.

5. The computer network file system of claim 4, wherein said location information further comprises a disk id that identifies a disk drive attached to a file server corresponding to said server id.

6. The computer network file system of claim 4, wherein said directory information comprises at least one Gnid-string.

7. The computer network file system of claim 6, wherein a one-to-one correspondence exists between said at least one Gnid-string and a directory stored on said first file server.

8. The computer network file system of claim 6, wherein said Gnid-string comprises a collection of gnids.

9. The computer network file system of claim 8, wherein each of said gnids comprises information for locating a specified gnode.

10. The computer network file system of claim 9, wherein said information for locating a specified gnode comprises a pointer to said specified gnode.

11. The computer network file system of claim 9, wherein said specified gnode comprises file attributes for a file corresponding to said gnode.

12. The computer network file system of claim 11, wherein said file attributes include at least one of a file id, a file access time, a file creation time, and a file modification time.

13. The computer network file system of claim 9, wherein said specified gnode comprises information for locating a first gee of a plurality of gees corresponding to said gnode.

14. The computer network file system of claim 13, wherein said plurality of gees comprises gnode gees and data gees.

15. The computer network file system of claim 14, wherein each of said gnode gees comprises information to specify an extent.

16. The computer network file system of claim 14, wherein each of said data gees comprises information to specify a first logical disk block and information to specify a disk that contains said first logical block.

17. The computer network file system of claim 13, wherein said plurality of gees further comprises parity gees.

18. The computer network file system of claim 17, wherein each of said parity gees comprises information regarding location of parity data for one or more preceding data gees in said plurality of gees.

19. The computer network file system of claim 13, wherein a parity group comprises a first set of one or more data gees and an associated parity gee.

20. The computer network file system of claim 19, wherein each data gee identifies a block of data and said parity gee identifies a parity block.

21. The computer network file system of claim 20, wherein each block of data and parity in said parity group is stored on a separate disk drive such that no single disk drive contains data from two blocks of said parity group.

22. The computer network file system of claim 19, wherein a size of a first parity group is independent of a size of a second parity group.

23. The computer network file system of claim 1, wherein directory information created by said first file server is mirrored on said second file server.

24. The computer network file system of claim 1, wherein said network fabric comprises a Fibre channel network.

25. The computer network file system of claim 1, wherein said network fabric comprises an ethernet network.

26. The computer network file system of claim 1, wherein said network fabric comprises an asynchronous transfer mode network.

27. The computer network file system of claim 1, wherein said network fabric comprises a first Fibre channel network and wherein said first file server communicates with one or more disk drives using a second Fibre channel network.

28. The computer network file system of claim 1, wherein files stored by said first file server and files stored by said second file server are located in a hierarchical directory structure having a common root directory, said first file system information comprising directory information that describes directories stored on said first file server, said second file system information comprising directory information that describes directories stored on said second file server, said first directory information comprising location information for finding said second directory information, said location information comprising a server id that identifies said second file server.

29. The computer network file system of claim 1, wherein files stored by said first file server and files stored by said second file server are located in a hierarchical directory structure having a common root directory, said first file system information comprising metadata for locating files stored on said second file server.

30. The computer network file system of claim 1, wherein said first file system information comprises first metadata that describes directories stored on said first file server, said file system information comprising second metadata that describes directories stored on said second file server, said first metadata comprising location information for locating said second metadata, said location information comprising a server id.

31. The computer network file system of claim 30, wherein said first metadata comprises a root directory.

32. The computer network file system of claim 30, wherein at least said first metadata comprises file attributes for one or more files stored by said first file server.

33. The computer network file system of claim 30, wherein at least said first metadata comprises information to specify a selected logical disk block of a selected file and information to specify a disk that contains said selected logical block.

34. The computer network file system of claim 30, wherein said metadata identifies data blocks and parity blocks corresponding to said data blocks.

35. The computer network file system of claim 30, wherein said metadata identifies parity groups, said parity groups comprising a plurality of information blocks, said information blocks comprising one or more data blocks, said information blocks further comprising a parity block, each of said information blocks stored on a different disk drive.

36. The computer network file system of claim 1, wherein a size of a first parity group is independent of a size of a second parity group.

37. The computer network file system of claim 1, wherein said first file server communicates with one or more disk drives using a Fibre channel network.

38. The computer network file system of claim 1, wherein said first file server communicates with one or more disk drives using InfiniBand.

39. The computer network file system of claim 1, wherein said first file server communicates with one or more disk drives using SCSI.

40. A method for storing data in a computer network, comprising:

loading first file system metadata on a first file server operably connected to a network fabric;

loading second file system metadata on a second file server connected to said network fabric, said first file system metadata and said second file system metadata comprising information to allow a client computer operably connected to said network fabric to locate a file stored by said first file server or stored by said second file server without prior knowledge as to which file server stores said file.

41. The method of claim 40, further comprising storing first file system directory information on said first file server, said first file system directory information describing a directory structure of a portion of the network file system whose directories are stored on said first file server, said first file system directory information comprising location information for a first file, said location information comprising a server id that identifies said second file server.

42. The method of claim 41, wherein said first file system directory information comprises a root directory.

43. The method of claim 40, further comprising storing first file system directory information on said first file server, said first file system directory information describing a directory structure of a portion of the network file system whose directories are stored on said first file server, said first file system directory information comprising location information for a first file, said location information comprising a server id that identifies a file server containing said first file.

44. The method of claim 43, wherein said file first system directory information comprises at least one Gnid-string.

45. The method of claim 44, wherein a correspondence exists between said at least one Gnid-string and a directory stored on said first file server.

46. The method of claim 44, wherein said Gnid-string comprises a collection of gnids.

47. The method of claim 46, wherein each of said gnids comprises information for locating a specified gnode.

48. The method of claim 47, wherein said information for locating a specified gnode comprises a pointer to said specified gnode.

49. The method of claim 47, wherein said specified gnode comprises file attributes for a file corresponding to said gnode.

50. The method of claim 49, wherein said file attributes include at least one of a file id, a file access time, a file creation time, and a file modification time.

51. The method of claim 47, wherein said specified gnode comprises information for locating a first gee of a plurality of gees corresponding to said gnode.

52. The method of claim 51, wherein said plurality of gees comprises gnode gees and data gees.

53. The method of claim 52, wherein each of said gnode gees comprises information to specify a logical block extent.

54. The method of claim 53, wherein each of said data gees comprises information to specify a first logical disk block and information to specify a disk that contains said first logical block.

55. The method of claim 52, further comprising defining a plurality of parity gees.

56. The method of claim 55, wherein each of said parity gees comprises information regarding location of parity data for one or more preceding data gees in said plurality of gees.

57. The method of claim 40, further comprising defining at least one parity group having a first parity group size, said at least one parity group comprising a parity block and one or more data blocks.

58. The method of claim 57, further comprising storing each of said data blocks and said parity block on different disk drives.

59. The method of claim 57, further comprising defining at least one parity group having a second parity group size.

60. The method of claim 40, further comprising:

mirroring said first file system directory information on said second file server.

61. The method of claim 40, wherein first file system directory information describes at least a portion of a hierarchical directory structure, said hierarchical directory structure spanning said first file server and said second file server, said first file system directory information comprising directory information that describes directories stored on said first file server, and wherein second file system directory information comprises at least a portion of said hierarchical directory structure comprising directory information that describes directories stored on said second file server, said first directory information comprising location information for finding said second directory information, said location information comprising a server id that identifies said second file server.

62. The method of claim 40, wherein file system directory information comprises first metadata that describes directories stored on said first file server, said file system directory information comprising second metadata that describes directories stored on said second file server, said first metadata comprising location information for locating said second metadata, said location information comprising a server id, said first metadata and said second metadata describing at least a portion of a hierarchical directory structure that spans both said first file server and said second file server.

63. The method of claim 62, wherein said first metadata comprises a root directory.

64. The method of claim 62, wherein at least said first metadata comprises file attributes for one or more files stored by said first file server.

65. The method of claim 62, wherein at least said first metadata comprises information to specify a selected logical disk block of a selected file and information to specify a disk that contains said selected logical block.

66. The method of claim 62, wherein said metadata identifies data blocks and parity blocks corresponding to said data blocks.

67. The method of claim 40, further comprising performing a directory lookup by sending a directory lookup request to said first file server, said first file server returning a directory file handle that points to a directory on said second file server.

69. The computer network file system of claim 68, wherein said directory structure comprises location information for a first file, said location information comprising a server id that identifies at least said first file server or said second file server.

70. The computer network file system of claim 68, wherein said directory structure comprises server ids of servers that contain sub-directories.

68. A computer network file system, comprising:

a first file server operably connected to a network fabric;

a second file server operably connected to the network fabric;

means for locating files stored by said first file server and means for locating files stored by said second file server by traversing a directory structure that spans at least a said first file server and said second file server.

71. A method for performing a file handle lookup on a computer network file system, comprising:

sending a root-directory lookup request to a first file server;

receiving a first lookup response from said first file server, said first lookup response comprising a server id of a second file server;

sending a directory lookup request to said second file server; and

receiving a file handle from said second file server.

72. The method of claim 71, said first lookup response comprising a directory file handle.

73. A method for performing file allocation on a computer network file system, comprising:

receiving a file allocation request in a first file server, said first file server owning a parent directory that is to contain a new file, said file allocation request comprising a file handle of said parent directory;

determining a selected file server from a plurality of file servers;

sending a file allocation request from said first server to said selected server;

creating metadata entries for said new file in file system data managed by said selected file server;

generating a file handle for said new file;

sending said file handle to said first file server; and

creating a directory entry for said new file in said parent directory.

74. The method of claim 73, wherein said directory entry for said new file comprises a gnid.

75. The method of claim 73, further comprising:

sending said file handle for said new file to a requester.